Seal for stoker bearings



July 8, 1952 P. c. MALMsrEN 2,602,679

SEAL FOR STOKER BEARINGS Filed July 8, 1946 Patented July 8, 1 952 1 5, A SEAL Foa s'roKER BEARINGS i; :.PhilipC. Malmsten, Milwaukee, Wis., assigner to A. 0.; Smith Corporation, Milwaukee, -Wis., a

.corporation of New York Application July s, 1946, serial No. 681,979 Y j lr 1 `Claim.

This invention relates to arseal for stoker beartings `and particularly has Vreference tothe seal between the feed screw: and'clutch drive shaft to prevent 'coal dust from accumulating in the bearings which-the clutch shaft operates.

The' principal objectfof the'in'vention is to seal bifftheybearings in-whichtheje1utch shaftof a 4stokerloperatesagainst approach of dust'to the bearings.

Another object is to seal off the clutch shaft bearings against dust by a seal which will not deteriorate in service.

These and other objects of the invention will appear hereinafter in connection with the following description of an embodiment of the invention as illustrated in the accompanying drawings.

In the drawings:

Figure 1 is a longitudinal sectional view of a portion of a stoker showing the seal of the invention between the clutch drive shaft and the stoker feed screw; and

Fig. 2 is an exploded perspective, with the parts separated to more clearly show the several parts of the seal.

The drawing shows a portion of a stoker comprising in general the feed screw II which is rotated within the feed screw tube 2 by the clutch drive shaft 3, interlocked therewith, as will be described, and in turn driven by a motor and clutch assembly, not shown.

The clutch drive shaft 3 rotates within the bearing 4 which is suitably secured within the bearing housing 5. The rear portion of the clutch shaft rotates within the clutch housing 6, which is shown only in part with the clutch removed, and the forward end or head I seats within the opening 8 of the socket 9 provided at the rear end of feed screw I.

The end 1 of clutch shaft 3 is square and the opening 8 of socket 9 is complementary thereto to provide the interlocking connection between the shaft and the feed screw by which the latter is rotated. The lock pin or bar IU is transversely disposed in aligned apertures of feed screw I and shaft 3 at the interlock therebetween in socket 9 to couple the two members axially together and prevent separation thereof by forward axial movement of the feed screw in operation.

Socket 9. is of generally conical shape and overlaps bearing housing 5 for a substantial distance.

The seal provided to protect bearing 4 from dust and the like comprises a felt washer or packing I I which is assembled around head 'I of shaft4 *ing 5.

Y 2 Y forward side and is heldin place by flange I2 of shaft 3 and the end of bearing housing 5. VThe washer I I closes the forward end of bearing hous- The periphery of the washer extends radially beyond housing 5 in its seat within socket 9.

The cup shaped generally thin metal washer I3 encircles fiange I2 of shaft 3. `The base of washer I3 is faced toward washer Il and the flange I4 thereof extends axially inwardly of bearing housing 5 to bearing 4 and underlaps the housing wall. The wall of the housing and Washer flange I4 provide a metal to metal seal therebetween.

The felt washer or'packing 'I5 which is of substantially less diameter than washer II encircles flange I2 of shaft 3 and seats within cup washer I3.

The seal is completed by the generally thin metal washer I6 which seats within cup washer I3 against felt washer I5. Washer I6, as with washer I5, is assembled around shaft 3 between bearing 4, and ange I2 of shaft 3 to secure the same in place and extends radially to flange I4 of cup washer I3. The bearing 4 is assembled on shaft 3 around the flange I'I thereon.

In order for dust to reach bearing 4 it would have to pass into the conical space between socket 9 and bearing housing 5, then between felt washer I I and the inner end of housing 5. From there the dust would have to travel between felt washer II and cup washer I3 down to flange I2 of shaft 3 and then outwardly between felt washer I5 and cup Washer I3 and past the outer peripheries of both felt washer I5 and the metal washer I6.

The felt Washers II and I5 which are in tight engagement with shaft 3 prevent any "axial movement of dust along the shaft to bearing 4 and the dust would also be restricted in such movement by cup washer I3 and metal washer I5.

The felt washers may be replaced by Washers of any suitable absorbent material which would tend to pick up and retain dust.

The invention is particularly applicable to a stoker bearing in which the protection of the bearing from dust is especially important due to the extensive movement of coal dust in the area of the bearing when the stoker feed screw is in operation. The double seal provided insures that no dust will reach the bearing.

Various embodiments of the invention may be employed within the scope of the accompanying claim.

I claim:

In a driving connection for a Stoker, a drive t said bearing, said seal comprising a Vfrusta` conical skirt 0n the end of said worm and extending axially over the bearing housing for a substantial distance from the open end thereof and providing a cup shaped recess for receivingA the open end of the bearing" housing, a fixed washer secured in the open end of the bearing housing by an oil tight t therewith and eXf-y i tending radially inward to an inner edge of the Washer adjacent tov the shaft, a second washer secured upon the shaft to rotate therewith inwardly of said stationary washer, said stationary washer having an inwardly extending iange at -its outer circumference extending along the inbearing housing, a felt washer confined under f Nurnber axial pressure in the recess between said rotary worm and said stationary washer, and a felt Washer confined under axial pressure between said stationary washer and said rotary washer, whereby coal dust tending t0 pass into said recess is substantially prevented from reaching the bearing by reason of the substantial radial extent 0f travel thereof required along the frictional end'surfaces of the felts in series to pass the seal.

` PHILIP C. `MALMSTEN.

Y REFERENCES CITED .The following references are of record in the le' of this, patent;

UNITED 'STATES PATENTS Name Date 1,066,276 Hockensmth July 1, 1913 1,569,751 Higgins Jan. 12, 1926 1,700,356 Harper r r r May 27, 1930 '1,917,674 Weaver eeea July 11, 1933 Y2,054,581 Deiaval-Crow Sept. 15, 1936 2,080,669 l\elson;r v..,.l 1 May 18, `1937 2,100,113 Travis Y e1 v vNov. 23, 1937 2,122,085 Castricone Y V Y.-.V. June 28,F 1938 2,251,450 Y Hanna Aug.5,i1941 2,441,294 Shafer anat-n n May 11. 1948 

